Refrigerant injector and surge drum arrangement



April 12, 1949. H. A. PHILLIPS 7 2,466,863

REFRIGERANT' INJECTOR AND SURGE DRUM ARRANGEMENT Filed July 5,1947 7 2 Sheets-Sheet 1 e? 1 QM IN VEN TOR.

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April 12, 1949. H. A. PHILLIPS 2,466,363

. REFRIGERANT INJECTOR AND SURGE DRUM ARRANGEMENT 2 Sheets-Sheet 2 Filed July 3, 1947 INVHVTOR.

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Patented Apr. 12, 1949 OFFICE REFRIGERANT INJECTOR AND SURGE DRUM ARRANGEMENT Harry A. Phillips, Chicago, Ill. Application July 3, 1947, Serial No. 758,903

7 Claims. (Cl. 62-115) The invention relates to refrigeration and has reference more particularly to an improved system of refrigeration and apparatus therefor including a plurality of evaporators each employing recirculating injector equipment in combination with a small surge drum for flooding the coils of its respective evaporator as disclosed and claimed in my Patent No. 2,123,021 granted July 5, 1938.

An object of the invention resides in the pro vision of refrigerating apparatus employing a plurality of evaporators in combination with improved structure which will make possible the use of simple recirculating injectors for the liquid refrigerant on flooded coils without requiring elaborate control means in connection with said plurality of evaporators.

A further object of the invention resides in the provision of refrigerating apparatus employing a pluralityof evaporators and which will incorporate a recirculating injector and a small surge drum on each evaporator to facilitate oil return while achieving economy in installation. In connection with refrigerating apparatus of this character the invention contemplates the provision of a suction line accumulator for receiving liquid refrigerant passed over from time to time by the various surge drums and in combination with said accumulator a drier coil is provided for evaporating any such liquid refrigerant which may be received by the suction line accumulator.

Another object of the invention is to provide refrigerating apparatus of the character described wherein the suction line accumulator will be provided with a drier coil connecting with the high pressure refrigerant line whereby any liquid refrigerant in the accumulator drum is evaporated and sumcient heat is removed from the high pressure refrigerant to effect condensation so that liquid flow of the refrigerant to the condenser-receiver will be free and unobstructed.

Another object of the invention is to provide a refrigerating system wherein oil return from the evaporators is assured even at small loads.

With these and various other objects in view, the invention may consist of certain novel features of construction and operation, as will be more fully described and particularly pointed out in the specification, drawings and claims appended hereto. q

In the drawings which illustrate an embodiment of the device and wherein like reference characters are used to designate like parts- Figure 1 is an elevational view illustrating a refrigerating system embodying the improvements of the invention;

Figure 4 is a fragmentary elevational view illustrating a modified form of refrigerating apparatus coming within the invention.

Referring to the drawings, the refrigerating system selected for illustrating the present invention consists of a compressor indicated by numeral in which is driven by the motor II, the said compressor and motor being suitably supported on the tank [2 comprising a condenser-receiver. The compressor has connection with the main suction line l3 through the suction line trap M. An accumulator drum I5 is interposed in the main suction line and said dllm'l receives the low pressure gaseous refrigerant from a plurality of evaporator coils l6, l1 and I8. The high pressure refrigerant line 20 leads from the compressor and has connection withthe coil 2| located within the accumulator drum l5. From the drum the high pressure refrigerant line is continued by pipe 22 which connects with the condenser-receiver at the left .end thereof. The liquid refrigerant such as ammonia is conducted from the condenser-receiver by line 23 providing the still 24 and which extends upwardly, for connection with the evaporators l6, l1 and I8, respectively. An oil return line 25 has connection with the bottom of the accumulator drum is at the right hand side thereof and said oil return line includes the coil 26 located within the still 24 and forming a heat exchanger therewith whereby any liquid refrigerantpassing over with the oil is evaporated. The connection 21 at the bottom of the coil conducts the oil return line to compressor l0. A by-pass 28 is provided in said connection leading to thesuction line trap M for returning evaporated refrigerant to the compressor.

The refrigerating system of the invention finds particular application when serving a plurality of evaporators employing surge drums and recirculating injectors respectively. For example, referring to the vaporator IE, it will be seen that the liquidrefrigerant line 3!! connecting with the line 23 supplies liquid refrigerant to the surge drum 3-l, there being interposed in the line 30 the valve 32 operated by float 33, Figure 3. In advance of valve 32 the liquid supply line 30 is provided with a by-pass connection 34 leading to the recirculating injector 35 provided with the nozzle 36, Figure 2. The recirculating injector also has connection through pipe 31 with th bottom of the surge drum 3| and accordingly said injector operates to recirculate liquid refrigerant through the coils of the evaporator l6 and which recirculating effect is facilitated by the injector action of the liquid refrigerant discharged by nozzle 36. The evaporated refrigerant from the coils upon entering the header 3B is conducted by the pipe 40 to the top of the surge drum 3| and from said drum the gaseous refrigerant is drawn oh by suction line 4| connecting with the main suction line It of the system. Any liquid refrigerant which may enter the surge drum will be collected at the bottom of the drum and eventually recirculated by the recirculating injector I! along with'some liquid refrigerant from the refrigerant supply line 23.

The evaporators l1 and it are constructed similar to evaporator 56, each including a surge drum 3|, a float operated valve 32, and a recirculating injector 35. The control of liquid refrigerant from the supply line 23 to the plurality of evaporators may be controlled thermostatically or otherwise by a solenoid valve 42. The evaporators are operatedso as to maintain their coils in a flooded condition and which is provided for by the surge drums and the float operated valves associated therewith. The liquid refrigerant surrounding the nozzle of each injector is supplied thereto by its particular sin'ge drum and includes recirculating refrigerant and some liquid refrigerant supplied by line 30. This liquid refrigerant is fed into the coils of the evaporator by the iniector action of the liquid refrigerant and gas issuing from the nozzle of theiniector. When the solenoid valve 42 remains open the evaporator is in continuous operation and liquid refrigerant as above described will be supplied to the nozzles of the injectors.

In a refrigerating system employing a plurality of evaporators it has been found desirable to employ small surge drums such as 3| in connection with each evaporator. The surge drums provide for flooded operation of'the coils, which in combination with the recirculating injectors has proven highly eflicient. However, there may be some passage of liquid refrigerant from the surge drums from time to time to the main suction line of the system. Accordingly, the invention contemplates the provision of an accumulator drum and a drier coil located within the drum. The drier coil 2|, as shown in Figure 1, has connection with the high pressure, high temperature gaseous refrigerant line 20 and said coil and the accumulator drum should have suf-- flcient surface to evaporate any liquid slop-over that may possibly occur from the surge drums. In operation the cool gaseous refrigerant in the accumulator drum will have a cooling effect on the coil removing sufficient heat from the high pressure, high temperature gaseous refrigerant in the coil to cause condensation so that liquid flow to the condenser-receiver will take place in a free and unobstructed manner.

With the refrigerating system of the invention it becomes possible to use simple liquid recirculating injector equipment onvflooded coils and which will not require an elaborate control method for controlling the multiple evaporators. Also the oil return to the compressor is simplifled since the cost of building small surge drums and one accumulator is generally less than that required to build large drums for each evaporator. Also the simplified oil return assures return of oil even at small loads.

In Figure 4 a modified refrigerating system is disclosed wherein the drier coil for the accumu-- lator drum includes a section of the liquid refrigerant line located beyond the condenser-receiver instead of in advance of the-same, as in Figure 1. The compressor H is driven by motor I with both elements being suitably supported .by the condenser-receiver tank H2. The compressor has connection with the main suction line 3 through the suction line trap lid and in accordance with the invention said main suction line includes an accumulator i It. The high pressure refrigerant line I20 from the compressor has connection directly with the condenser-receiver. Liquid refrigerant from the condenser-receiver is delivered by the line I23 providing the still i2 and this liquid line beyond the still includes a coil i23a which enters the accumulator drum to provide the drier coil for evaporating any liquid refrigerant which may accumulate in the drum. A heat exchanging effect takes place between-the high temperature liquid refrigerant and the low pressure gas in the accumulator which has the effect of evaporating any liquid refrigerant which may slop over from the plurality of evaporators connecting with the system and at the same time the liquid refrigerant is materially cooled in advance of delivery to the evaporators. The bottom of the accumulator drum has connection with line I25 for draining oil from the drum and said line connects in turn with the coil I26 located within the still as previously described. The oil is eventually returned to the compressor by lin l2'| and by the bypass I28 delivers to the compressor any gaseous refrigerant evaporated by the still.

It will be understood that a plurality of evaporators are connected in parallel between the liquid refrigerant line I23 and the suction line H3 and that each evaporator includes a surg drum and a recirculating injector asdescribed in connection with Figure 1.

The invention is not to be limited to or by de-- tails of construction of the particular embodiment thereof illustrated by the drawings as various forms of the device will of course be apparent to thoseskilled in the art without departing from th spirit of the invention or the scope of the claims.

What is claimed is:

1. In a refrigerating system, the combination with evaporator means, of a suction line connecting the evaporator means with a compressor, a high pressure line for supplying liquid refrigerant to the evaporator means, an accumulator drum in the suction line, said high pressure line including a coil having location within the drum to provide a heat interchanger whereby any liquid refrigerant in the drum is evaporated, and a connection leading from the bottom of the drum for draining any oil accumulating in the drum and returning the same to the compressor.

2. In a refrigerating system, the combination with a plurality of evaporators of the flooded type, of a suction line connecting with the discharge ends of said evaporators, a high pressure refrigerant line for supplying liquid refrigerant to the evaporators, an accumulator drum in the suction line, a coil in said drum connecting with and forming'part of said high pressure line to provide a heat interchanger whereby any liquid refrigerant in the drum is evaporated, and a connection leading from the bottom of the drum for draining any oil accumulating in the drum.

3. A refrigerating system as defined by claim 2 additionally including a still for the oil connection provided by the high pressure refrigerant line for evaporating any liquid refrigerant in the connection which may have been drained thereby from the drum.

4. In a refrigerating system using ammonia or other refrigerant llquids'lighter than and immiscible in oil, the combination with a plurality of evaporators, of a compressor, a suction line connecting the evaporators with the low pressure side auaaos of the compressor, a high pressure refrigerant line connecting the high pressure side of the compressor with the evaporators, an accumulator drum. interposed in the suction line between the evaporators and the compressor, a coil provided by the high pressure refrigerant line and having location in the drum, and a connection leading from the bottom of the drum for draining any oil accumulating in the drurn, said connection joining with the compressor whereby said oil is returned thereto.

5. A refrigerating system as defined by claim 4, additionally including a heat interchanger for evaporating any liquid refrigerant in the oil by bringing the oil connection into heat exchanging relation with the high pressure refrigerant line.

6. In a refrigerating system using ammonia or other refrigerant liquids lighter than and immiscible in oil, the combination with a plurality of evaporators', of a compressor, a receiver for liquid refrigerant, a suction line connecting the discharge ends of the evaporators with the low pressure side of the compressor, an accumulator drum interposed in the suction line between the evaporators and the compressor, a refrigerant line connesting the high pressure side of the compressor with the receiver and including a coil having loca tion within the accumulator drum, a liquid refrigerant line connecting with the receiver for supplying liquid refrigerant to the evaporators, and a pipe having connection with the bottom of the accumulator drum for draining any oil accumulating in the drum, said pipe joining with the compressor whereby said oil is returned thereto.

7. A refrigerating system as defined by claim 6, additionally including a heat interchanger for evaporating any liquid refrigerant in the oil by bringing the oil pipe into heat exchanging relation with the liquid refrigerant line.

HARRY A. PHILLIPS.

REFERENCES CITED The following references are of record in the 

